1. Field of the Invention
The present invention concerns a multi-channel amplifier as well as a transmission arrangement with such a multi-channel amplifier.
2. Description of the Prior Art
Multi-channel amplifiers are generally known. For example, in the form of multi-channel radio-frequency power amplifiers they are used as transmission amplifiers in magnetic resonance systems, and in radar and other radio-frequency transmission systems.
A multi-channel amplifier has a number of inputs via which respective input signals can be supplied to the multi-channel amplifier. Furthermore, a multi-channel amplifier has an amplification stage with a number of amplifier channels. The amplifier channels are connected with the inputs and the outputs. A maximum of one channel power can be emitted from each amplifier channel. The input signals supplied to the multi-channel amplifier can be amplified into output signals by means of the amplifier channels. A multi-channel amplifier has a number of outputs from which the output signals are emitted from the multi-channel amplifier.
For some uses of multi-channel amplifiers, it is not known in advance which output should emit which power. The multi-channel amplifier is therefore normally designed such that a limit power (load limit) can be emitted at each output, and such that the power that can be emitted in total by the multi-channel amplifier over all outputs is equal to the sum of the limit powers. Conventionally the limit power is fixed for each output by the design of the multi-channel amplifier. It is thus always set to a maximum value. This leads to large, expensive multi-channel amplifiers. Particularly for use in mains adapters and cooling devices, this means that the multi-channel amplifier must be designed such that it can handle or dissipate the sum of the limit powers.